Pacific Palisades, CA (My Sportsbook) - Dustin Johnson fired a seven-under 64 on Thursday to lead the Northern Trust Open, while two-time defending champion Phil Mickelson ditched his controversial wedge and labored to a 72.

Johnson, a two-time PGA Tour winner who likes the way Riviera fits his eye, had seven birdies in a flawless round to take a one-shot lead over Kevin Stadler and Argentina's Andres Romero.

Ricky Barnes and Brandt Snedeker were another stroke further back at 66, while Steve Stricker, Cameron Beckman and Steve Lowery each shot 67s.

A talented group at 68 included Ernie Els, David Duval, Rory Sabbatini, Jesper Parnevik, Scott Verplank, Stephen Ames, Luke Donald and 18-year-old Japanese star Ryo Ishikawa.

As promised, Mickelson didn't use the Ping Eye 2 wedge that caused a stir last week at Torrey Pines and prompted veteran Scott McCarron to accuse Lefty of cheating for exploiting a loophole in the new regulations against using clubs with square grooves.

The off-course turmoil caused by McCarron's comments gave way to on-course travails as Mickelson had a rare off-day at a tournament where he is the all time leading money winner.

Trying to become the first player to win this tournament three straight years, Mickelson had four bogeys in his last seven holes after he rallied to get as low as three-under par. He nearly made a miraculous birdie during that stretch at the 17th, where he escaped a bunker and almost holed-out for eagle from 200 yards.

But Mickelson's birdie putt skirted the edge of the cup and he made par. He closed with a bogey at the 18th after missing a six-footer.

Johnson, 25, said he likes the way Riviera fits his eye -- he tied for 10th last year -- and that was apparent when he birdied three of his first five holes for a hot start.

He chipped to eight feet on the 11th, holed a 60-foot putt for birdie at the 12th, then knocked a nine-iron to 15 feet to set up his third birdie at the 14th. He added another birdie at the 17th to make the turn in 32 shots.

"Had good vibes going all day," Johnson said.

He two-putted from eight feet for a birdie at No. 1, then made back-to-back birdies later on to take the clubhouse lead at a course he considers one of the best on the PGA Tour.

"It's just a fun course to play," said Johnson. "You've got to hit every club in your bag, and you've got to be smart coming into the greens just because you want to hit yourself on the right side of the hole."

Stadler had a lot of fun early on, making six birdies before the turn and seven in his first 10 holes to tie Johnson's clubhouse lead. But he bogeyed his 11th hole -- No. 2 -- to fall back, and didn't make another birdie the rest of the way.

A four-time winner on the Nationwide Tour, Stadler is trying for his first PGA Tour victory.

Romero, the 2008 PGA Rookie of the Year, had eight birdies and a costly double-bogey at No. 9, where he went against the club advice of his caddy and hit a six-iron into the bunker.

"My caddie was telling me to hit a seven-iron just to the front of the green, but I'm so stubborn I stayed with the six, and it buried in the wall of the bunker," Romero said.

Romero, 28, birdied his last four holes to get within one shot of Johnson's clubhouse lead. He is looking to bounce back from a disappointing 2009 season that saw him miss eight cuts and get disqualified in New Orleans, where he captured his only win a year earlier.

"This is a good week to start playing good golf," said Romero. "After the year I had last year, I think it's a good course. It suits me and my golf, my game, and luckily I started well."

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